﻿//图片切割
j.ImgCropper = new j.Class().extend({
    //容器对象,控制层,图片地址
    initialize: function(container, handle, url, options) {
        this._Container = j.$(container); //容器对象
        this._layHandle = j.$(handle); //控制层
        this.Url = url; //图片地址

        this._layBase = this._Container.appendChild(document.createElement("img")); //底层
        this._layCropper = this._Container.appendChild(document.createElement("img")); //切割层
        this._layCropper.onload = j.bind(this, this.SetPos);
        //用来设置大小
        this._tempImg = document.createElement("img");
        //        this._tempImg.style.display = "none";
        //        window.document.appendChild(this._tempImg);
        this._tempImg.onload = j.bind(this, this.SetSize);


        this.SetOption(options);

        this.Opacity = Math.round(this.options.Opacity);
        this.Color = this.options.Color;
        this.Width = Math.round(this.options.Width);
        this.Height = Math.round(this.options.Height);
        this.Scale = !!this.options.Scale;
        this.Ratio = Math.max(this.options.Ratio, 0);
        this.minWidth = Math.round(this.options.minWidth);
        this.minHeight = Math.round(this.options.minHeight);

        if (this.Ratio == 0)
            this.Ratio = this.minWidth / this.minWidth;

        //设置预览对象
        var oPreview = j.$(this.options.Preview); //预览对象
        if (oPreview) {
            oPreview.style.position = "relative";
            oPreview.style.overflow = "hidden";
            this.viewWidth = Math.round(this.options.viewWidth);
            this.viewHeight = Math.round(this.options.viewHeight);
            //预览图片对象
            this._view = oPreview.appendChild(document.createElement("img"));
            this._view.style.position = "absolute";
            this._view.onload = j.bind(this, this.SetPreview);
        }
        //设置拖放
        this._drag = new j.Drag(this._layHandle, { Limit: true, onMove: j.bind(this, this.SetPos), Transparent: true, Ratio: this.Ratio, Min: this.Min, minWidth: this.minWidth, minHeight: this.minHeight });
        //设置缩放
        this.Resize = !!this.options.Resize;
        if (this.Resize) {
            var op = this.options, _resize = new j.Resize(this._layHandle, { Max: true, onResize: j.bind(this, this.SetPos) });
            //设置缩放触发对象
            op.RightDown && (_resize.Set(op.RightDown, "right-down"));
            op.LeftDown && (_resize.Set(op.LeftDown, "left-down"));
            op.RightUp && (_resize.Set(op.RightUp, "right-up"));
            op.LeftUp && (_resize.Set(op.LeftUp, "left-up"));
            op.Right && (_resize.Set(op.Right, "right"));
            op.Left && (_resize.Set(op.Left, "left"));
            op.Down && (_resize.Set(op.Down, "down"));
            op.Up && (_resize.Set(op.Up, "up"));
            //最小范围限制
            this.Min = !!this.options.Min;
            //设置缩放对象
            this._resize = _resize;
        }
        

        //设置样式
        this._Container.style.position = "relative";
        this._Container.style.overflow = "hidden";
        this._layHandle.style.zIndex = 200;
        this._layCropper.style.zIndex = 100;
        this._layBase.style.position = this._layCropper.style.position = "absolute";
        this._layBase.style.top = this._layBase.style.left = this._layCropper.style.top = this._layCropper.style.left = 0; //对齐
        //初始化设置
        this.Init();
    },
    //设置默认属性
    SetOption: function(options) {
        this.options = {//默认值
            Opacity: 50, //透明度(0到100)
            Color: "", //背景色
            Width: 0, //图片高度
            Height: 0, //图片高度
            //缩放触发对象
            Resize: false, //是否设置缩放
            Right: null, //右边缩放对象
            Left: null, //左边缩放对象
            Up: null, //上边缩放对象
            Down: null, //下边缩放对象
            RightDown: null, //右下缩放对象
            LeftDown: null, //左下缩放对象
            RightUp: null, //右上缩放对象
            LeftUp: null, //左上缩放对象
            Min: false, //是否最小宽高限制(为true时下面min参数有用)
            minWidth: 50, //最小宽度
            minHeight: 50, //最小高度
            Scale: false, //是否按比例缩放
            Ratio: 0, //缩放比例(宽/高)
            //预览对象设置
            Preview: null, //预览对象
            viewWidth: 0, //预览宽度
            viewHeight: 0//预览高度
        };
        j.extend(this.options, options || {});
    },
    //初始化对象
    Init: function() {
        //设置背景色
        this.Color && (this._Container.style.backgroundColor = this.Color);
        //设置图片
        this._tempImg.src = this._layBase.src = this._layCropper.src = this.Url;
        //设置透明
        if (j.Browser.isIE) {
            this._layBase.style.filter = "alpha(opacity:" + this.Opacity + ")";
        } else {
            this._layBase.style.opacity = this.Opacity / 100;
        }
        //设置预览对象
        this._view && (this._view.src = this.Url);
        //设置缩放
        if (this.Resize) {
            with (this._resize) {
                Scale = this.Scale; Ratio = this.Ratio; Min = this.Min; minWidth = this.minWidth; minHeight = this.minHeight;
            }
        }
    },
    //设置切割样式
    SetPos: function() {
        //ie6渲染bug
        if (j.Browser.isIE6) { with (this._layHandle.style) { zoom = .9; zoom = 1; }; };
        //获取位置参数
        var p = this.GetPos();
        //按拖放对象的参数进行切割
        this._layCropper.style.clip = "rect(" + p.Top + "px " + (p.Left + p.Width) + "px " + (p.Top + p.Height) + "px " + p.Left + "px)";
        //设置预览
        this.SetPreview();
    },
    //设置预览效果
    SetPreview: function() {
        if (this._view) {
            //预览显示的宽和高
            var p = this.GetPos(), s = this.GetSize(p.Width, p.Height, this.viewWidth, this.viewHeight), scale = s.Height / p.Height;
            //按比例设置参数
            var pHeight = this._layBase.height * scale, pWidth = this._layBase.width * scale, pTop = p.Top * scale, pLeft = p.Left * scale;
            //设置预览对象
            with (this._view.style) {
                //设置样式
                width = pWidth + "px"; height = pHeight + "px"; top = -pTop + "px "; left = -pLeft + "px";
                //切割预览图
                clip = "rect(" + pTop + "px " + (pLeft + s.Width) + "px " + (pTop + s.Height) + "px " + pLeft + "px)";
            }
        }
    },
    //设置图片大小
    SetSize: function() {
        var s = this.GetSize(this._tempImg.width, this._tempImg.height, this.Width, this.Height);
        //设置底图和切割图
        this._layBase.style.width = this._layCropper.style.width = s.Width + "px";
        this._layBase.style.height = this._layCropper.style.height = s.Height + "px";
        //设置拖放范围

        this._drag.mxRight = s.Width; this._drag.mxBottom = s.Height;
        this._drag.resetDragBox();
        //设置缩放范围
        if (this.Resize) { this._resize.mxRight = s.Width; this._resize.mxBottom = s.Height; }
    },
    //获取当前样式
    GetPos: function() {
        with (this._layHandle) {
            return { Top: offsetTop, Left: offsetLeft, Width: offsetWidth, Height: offsetHeight }
        }
    },
    //获取尺寸
    GetSize: function(nowWidth, nowHeight, fixWidth, fixHeight) {
        var iWidth = nowWidth;
        var iHeight = nowHeight;
        var scale = iWidth / iHeight;
        //按比例设置
        if (fixHeight) {
            iWidth = (iHeight = fixHeight) * scale;
        }
        if (fixWidth && (!fixHeight || iWidth > fixWidth)) {
            iHeight = (iWidth = fixWidth) / scale;
        }
        //返回尺寸对象
        return { Width: iWidth, Height: iHeight }
    }
});